My 12-year-old was just diagnosed with ADHD. Shouldn't we have known by now?

Not necessarily. In order to meet the criteria for the diagnosis of attention deficit hyperactivity disorder (ADHD), a child needs to have shown some symptoms before the age of 7. That said, the hallmark symptoms of inattention, hyperactivity, and impulsivity can be related to all sorts of conditions, including depression, anxiety, and hearing difficulties. Because teachers, doctors, and parents are often reluctant to "label" a child if they aren't sure, later diagnoses are common. In fact, they're rising among children 12 to 17. Still, if this is catching you by surprise, it's worth talking to your doctor or even seeking a second opinion.

Pediatrician Claire McCarthy, M.D., is medical director of the Martha Eliot Health Center in Boston. Send her your health questions!

Stumble Upon Facebook Del.icio.us Google Yahoo Digg it